/**
 * Copyright (C) 2009 - 2013 SC 4ViewSoft SRL
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.android.settings.audio.peq.peq.achart.util;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.TreeMap;

/**
 * This class requires sorted x values
 */
public class IndexXYMap<K, V> extends TreeMap<K, V> {
    private final List<K> indexList = new ArrayList<K>();

    private double maxXDifference = 0;

    public IndexXYMap() {
        super();
    }

    public V put(K key, V value) {
        indexList.add(key);
        updateMaxXDifference();
        return super.put(key, value);
    }

    public V put(int index, K key, V value) {
        indexList.add(index, key);
        updateMaxXDifference();
        return super.put(key, value);
    }

    private void updateMaxXDifference() {
        if (indexList.size() < 2) {
            maxXDifference = 0;
            return;
        }

        if (Math.abs((Double) indexList.get(indexList.size() - 1)
                - (Double) indexList.get(indexList.size() - 2)) > maxXDifference)
            maxXDifference = Math.abs((Double) indexList.get(indexList.size() - 1)
                    - (Double) indexList.get(indexList.size() - 2));
    }

    public double getMaxXDifference() {
        return maxXDifference;
    }

    public void clear() {
        updateMaxXDifference();
        super.clear();
        indexList.clear();
    }

    /**
     * Returns X-value according to the given index
     *
     * @param index
     * @return the X value
     */
    public K getXByIndex(int index) {
        return indexList.get(index);
    }

    /**
     * Returns Y-value according to the given index
     *
     * @param index
     * @return the Y value
     */
    public V getYByIndex(int index) {
        K key = indexList.get(index);
        return this.get(key);
    }

    /**
     * Returns XY-entry according to the given index
     *
     * @param index
     * @return the X and Y values
     */
    public XYEntry<K, V> getByIndex(int index) {
        K key = indexList.get(index);
        return new XYEntry<K, V>(key, this.get(key));
    }

    /**
     * Removes entry from map by index
     *
     * @param index
     */
    public XYEntry<K, V> removeByIndex(int index) {
        K key = indexList.remove(index);
        return new XYEntry<K, V>(key, this.remove(key));
    }

    public int getIndexForKey(K key) {
        return Collections.binarySearch(indexList, key, null);
    }
}
